74 



have presented a calculation or can suggest any single experiment which would 

 prove recapture, but on examining the chemical evidence I cannot think of an 

 alternative. 



BURTON: One must remember that Dr. Allen reached the same conclusion 

 as Dr. Magee, starting in an entirely different way. That does not prove that 

 Dr. Magee is right, but it does not prove that he is necessarily wrong. 



MAGEE: Samuel and I didn't have any preconceived ideas as to how this 

 thing was going to come out. We just wanted to put a complete model together 

 and, as you see, there are still many loose ends. I don't want to say that any 

 one of the things that I have presented is right. However, I didn't want to pre- 

 sent a model for the chemical effects and conclude that the radicals are formed 

 in very small regions without suggesting how this could happen. I gave only a 

 sort of rough, general picture, which seems to be in agreement with a number 

 of types of experimental observations, and I don't want you to think that I have 

 any particular confidence in any one of the steps. The complete picture may be 

 useful. That is my only point in presenting it. 



PLATZMAN: My own view is that it is quite impossible, at the present 

 time, to choose between the two alternatives presented by Dr. Magee and by my- 

 self. The most that we can hope for, at the moment, is perhaps a better recog- 

 nition of these alternatives. I think that what Dr. Magee has done constitutes a 

 very important advance. He has constructed the general kinetics of the chemical 

 consequences of irradiation from some definite assumptions concerning the bas- 

 ic mechanism, and that is very important. But from long-time experience in 

 chemistry we have learned to be wary about drawing conclusions as to the validi- 

 ty of fundamental mechanisms from the fact that their consequences seem to 

 agree with the experimental facts. It has been proved time and time again that 

 an incorrect mechanism can be in apparent agreement with experiment. My own 

 approach has been at the opposite pole from that of Dr. Magee. I have started 

 with the basic physical interactions of electron and medium and tried to find the 

 chemical consequences to which they lead. These fundamental interactions have 

 never before been considered properly. On the other hand, my work has not yet 

 progressed to the stage in which the kinetics are computed. I hope that before 

 long this may be possible. Ultimately, the final theory will very likely include 

 a good deal from both methods of approach. 



BURTON: I think this is a good time to quote O.K. Rice. He said: "The 

 best you can say for any mechanism is that neither it nor any other that you have 

 not thought of is necessarily incorrect." 



